JPH07294026A - Refrigerator - Google Patents

Abstract

PURPOSE:To always supply suitable refrigerant gas to a compressor by controlling liquefied refrigerant discharged from a gas cooler by switching the channel of bypass circuit means in a refrigerator which has the cooler between a tube communicating with the cylinder of the compressor and a tube communicating with a compressor shell. CONSTITUTION:A gas cooler circuit having a gas cooler 2 is provided between a tube communicating with the cylinder of a compressor 1 and a tube communicating with a compressor shell. The inlet tube 2a of the cooler is connected to the suction tube 1d of the compressor by a bypass tube 11a. If the ambient temperature of the compressor 1 detected by an ambient air temperature detector 9a becomes a predetermined value or less, a controller 8 opens a solenoid switching valve 7 provided at the tube 11a. Thus, the part of high-temperature and high-pressure refrigerant discharged from the compressor 1 to the tube 2a is fed to the tube 11a and introduced to the tube 1b of the compressor 1 through a throttle unit 12, thereby preventing an increase in the liquefied refrigerant fed from the cooler 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating device installed in a refrigerating showcase or the like.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show a conventional refrigeration system, which is a high-pressure shell type compressor 1 such as a rotary compressor, a condenser 3, a pressure reducing device 4, a cooler 5 and an accumulator 6. Are sequentially connected by a refrigerant pipe to form a main refrigerant circuit of the refrigeration cycle. A gas cooler 2 is provided between a gas cooler inlet pipe 2a connected to the outlet side of the compressor 1 of the main refrigerant circuit and a gas cooler outlet pipe 2b connected to the inlet side of the compressor 1 to form a gas cooler circuit. Form. The gas cooler 2 is composed of a radiator such as an air-cooled heat exchanger.

As shown in FIG. 10, the compressor 1 has a motor 1a and a cylinder 1b in a compressor shell 1e. A suction pipe 1d forming a part of a refrigerant pipe is connected to the cylinder 1b. Similarly, the discharge pipe 1c forming a part of the refrigerant pipe is connected to the cylinder 1b side of the compressor shell 1e, the gas cooler inlet pipe 2a is connected to the cylinder 1b, and the gas cooler outlet pipe 2b is connected to the compressor shell 1e.
Connected to the motor 1a side.

Next, the operation will be described. The low-temperature low-pressure gas refrigerant sucked into the compressor 1 from the suction pipe 1d is compressed by the cylinder 1b to become high-temperature high-pressure, and the cylinder 1b
Enters the gas cooler 2 through the gas cooler inlet pipe 2a connected to. The refrigerant gas is cooled by the gas cooler 2 to have a medium temperature and high pressure, passes through the gas cooler outlet pipe 2b and enters the shell 1e of the compressor 1, and the internal motor 1
While cooling a and the cylinder 1b, they pass through the gap, exit from the discharge pipe 1c to the main refrigerant circuit, and enter the condenser 3.

Then, the refrigerant gas that has entered the condenser 3 is condensed here, then decompressed by the decompression device 4 and evaporated by the cooler 5 to perform a cooling action. The refrigerant that has been cooled serves as a low-temperature low-pressure gas refrigerant again and returns to the compressor 1.

The gas cooler 2 has a high pressure inside the shell 1e, such as a rotary compressor, and the inside of the shell 1e cannot be cooled by the sucked refrigerant. This is to prevent internal overheating by sending it to the compressor 1. In particular, for example R
The gas cooler 2 is indispensable when a refrigerant having a large adiabatic index such as -22 and having a high discharge temperature is used at a low evaporation temperature to increase the compression ratio. FIG. 11 shows
This is shown in a Mollier curve diagram, and part A shows heat dissipation in the gas cooler 2.

[0007]

The gas cooler 2 has various environmental conditions in which the refrigerating showcase is used, that is,
It is necessary that the cooler 5 can be used for a wide range of evaporation temperature, and therefore the capacity of the gas scroller 2 is high under a high load operating condition such as when the ambient temperature of the compressor 1 is high. Even if the capacity of the gas cooler 2 (the heat dissipation capacity of the gas cooler 2) decreases, the lower limit capacity of the size that can prevent overheating of the compressor 1 and the gas cooler like operation under low outside air conditions. The refrigerant must not liquefy at the outlet of the gas cooler even in a low load operating state where the capacity of No. 2 (heat dissipation capacity of the gas cooler 2) is large, and the upper limit capacity that can maintain the overheated state must be satisfied.

In the conventional refrigeration system, if the capacity of the gas cooler 2 is set to be large so that it can be used under high load operation, when the ambient temperature of the compressor 1 becomes low, the Mollier curve diagram of FIG. As shown by a solid line, the refrigerant gas returns from the gas cooler 2 to the compressor 1 in a state where a part of the refrigerant gas is liquefied. For this reason, the lubricating oil is diluted with the liquid refrigerant in the compressor 1, and as a result, poor lubrication occurs, or the sliding portion is damaged due to foaming inside the compressor 1, washing of the lubricating oil film, and the like. The machine 1 may be damaged.

The object of the present invention is to eliminate the disadvantages of the prior art. Firstly, the use conditions of the refrigerating and refrigerating showcase in which the refrigerating apparatus is installed, that is, the conditions such as the load of the compressor and the ambient temperature. Even if there is a change in temperature, a proper refrigerant gas can be sent from the gas cooler to the compressor, and secondly, the proper refrigerant gas is provided to the compressor with fine control. is there.

[0010]

In order to achieve the above object, the present invention firstly connects a main refrigerant circuit composed of a compressor, a condenser, a pressure reducing device and a cooler with a cylinder of the compressor. In a refrigerating device having a gas cooler circuit composed of a gas cooler connected between a pipe that communicates with the inside of the compressor shell and a pipe that communicates with the inside of the compressor shell, detection that detects that part of the refrigerant discharged from the gas cooler has liquefied Means, by-pass circuit means for bypassing the main refrigerant circuit for preventing the liquefaction in the gas cooler by heating the suction refrigerant of the compressor with the high pressure refrigerant, and the flow of the bypass circuit means by the output from the detection means. The gist is to provide a control means for controlling the opening and closing of the road.

Secondly, the gist is that the detecting means is a temperature detector for detecting the ambient air temperature.

Thirdly, a temperature detector for detecting the temperature of any of the high temperature portion of the refrigeration cycle, such as between the gas cooler inlet pipe and the gas cooler outlet pipe, the discharge pipe from the compressor, the compressor shell, etc. That is the summary.

Fourthly, the detecting means has a temperature between a gas cooler inlet pipe and a gas cooler outlet pipe, a discharge pipe from the compressor, a compressor shell, or the like, at a high temperature portion of the refrigeration cycle,
The gist of the present invention is that it is a plurality of temperature detectors that respectively detect the two-phase temperature of the condenser.

Fifth, a temperature detector for detecting the temperature of a high temperature portion of the refrigeration cycle such as a discharge pipe from the compressor, a compressor shell, etc. between the gas cooler inlet pipe and the gas cooler outlet pipe. And a pressure detector for detecting the condensation pressure.

Sixth, the bypass circuit means is a bypass pipe connecting the gas cooler inlet pipe and the compressor suction pipe, and the flow passage opening / closing means and the expansion device are provided in the middle of the bypass pipe. Is the gist.

Seventh, the bypass circuit means is a bypass pipe which branches the condenser outlet pipe and is provided with a heat exchange section for exchanging heat with the compressor suction pipe, and the tip of the bypass pipe serves as the condenser outlet pipe. The gist of the present invention is that the flow path opening / closing means is provided in the condenser outlet pipe, which is the main refrigerant circuit located on the upstream side of the connection point and on the downstream side of the branch point after the connection.

Eighthly, the control means operates the flow path opening / closing means of the bypass circuit means when a plurality of detection means are provided and the difference between the detection values input from the plurality of detection means becomes a certain value or less. The gist is to output a signal.

Ninth, the control means has a gist of controlling to change the opening / closing degree of the flow path opening / closing means of the bypass circuit means in accordance with the detection value input from the detection means.

[0019]

According to the present invention described in claim 1, when a part of the refrigerant discharged from the gas cooler is liquefied when the ambient temperature is low, this state is detected by the detection means, and the detection signal is controlled from there. Enter in the means. The control means outputs the detection signal to the flow path opening / closing means of the bypass circuit means, heats the suction refrigerant of the compressor by the high pressure refrigerant, and sends the high temperature refrigerant to the gas cooler. Therefore, even if the refrigerant is cooled here, it does not liquefy, the liquefaction in the gas cooler is prevented, and the liquefied refrigerant does not enter the compressor from the gas cooler.

According to the second aspect of the present invention, in addition to the above operation, when the ambient temperature is low, the ambient air temperature in which the refrigeration system is installed is detected by a temperature detector that detects the ambient air temperature. Then, this detected temperature signal is input to the control means. Therefore, the control means determines from this temperature that the refrigerant discharged from the gas cooler is in a state of being easily liquefied.

According to the present invention of claim 3, claim 1
In addition to the effect of the invention described above, when the ambient temperature is low, any one of the high temperature refrigeration cycle parts such as the gas cooler inlet pipe and the gas cooler outlet pipe, the discharge pipe from the compressor, the compressor shell, etc. When the temperature is detected by the temperature detector, this detected temperature signal is input to the control means. Therefore,
The control means determines from this temperature that the refrigerant discharged from the gas cooler is in a state of being easily liquefied.

According to the invention of claim 4, claim 1
In addition to the effect of the invention described above, when the ambient temperature is low, any one of the high temperature refrigeration cycle parts such as the gas cooler inlet pipe and the gas cooler outlet pipe, the discharge pipe from the compressor, the compressor shell, etc. When the temperature and the two-phase temperature of the condenser are detected by the respective temperature detectors, these detected temperature signals are input to the control means. Therefore, the control means determines from these two temperatures that the refrigerant discharged from the gas cooler is in a state of being easily liquefied.

According to the present invention of claim 5, claim 1
In addition to the function of the described invention, between the gas cooler inlet pipe and the gas cooler outlet pipe when the ambient temperature is low,
When the temperature detector detects the temperature of one of the high temperature parts of the refrigeration cycle, such as the discharge pipe from the compressor or the compressor shell, when the pressure detector detects the condensation pressure, these detected temperatures The signal and the detected pressure signal are input to the control means.
Therefore, the control means determines from these two temperatures and pressures that the refrigerant discharged from the gas cooler is in a state of being easily liquefied.

According to the present invention of claim 6, claim 1
In addition to the operation according to the invention described above, when the ambient temperature of the compressor is low, a state in which a part of the refrigerant discharged from the gas cooler is liquefied is detected by the detection means, and if a detection signal is input from this to the control means, The control means receives the detection signal and outputs it to the flow path opening / closing means provided in the bypass circuit means to open the flow path. As a result, a part of the high-temperature high-pressure refrigerant discharged from the compressor to the gas cooler inlet pipe flows into the bypass circuit and mixes with the suction refrigerant in the compressor suction pipe through the expansion device, so that the suction refrigerant to the compressor is heated. As a result, the refrigerant sent from the compressor to the gas cooler is not liquefied even if it is cooled here.

According to the present invention of claim 7, claim 1
In addition to the operation according to the invention described above, when the ambient temperature of the compressor is low, a state in which a part of the refrigerant discharged from the gas cooler is liquefied is detected by the detection means, and if a detection signal is input from this to the control means, The control means receives the detection signal and outputs it to the opening / closing means of the flow path provided in the condenser outlet pipe to close it. As a result, the refrigerant from the condenser flows into the bypass circuit and heats the refrigerant in the compressor suction pipe via the heat exchange section provided in the bypass circuit. As a result, the refrigerant sent from the compressor to the gas cooler is not liquefied even if it is cooled here.

According to the present invention described in claim 8, claim 1
In addition to the operation according to the invention described above, the control means, when a plurality of detection means are provided, causes the flow path opening / closing means of the bypass circuit to operate when the difference between the detection values input from the plurality of detection means becomes equal to or less than a certain value. Since the operation signal is output, it is possible to determine the liquefaction of the refrigerant from a plurality of data, and the accuracy is improved.

According to the present invention of claim 9, claim 1
In addition to the operation of the invention described above, the control means controls so as to change the degree of opening / closing of the flow path opening / closing means of the bypass circuit in accordance with the detection value input from the detection means, so that the compressor is adapted to the degree of liquefaction. It is possible to heat the refrigerant sucked into the tank and obtain a more appropriate operating condition.

[0028]

【Example】

Example 1. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a refrigerant piping diagram showing a first embodiment of a refrigerating apparatus of the present invention. The refrigerating cycle has the same configuration as the conventional example shown in FIG. 9, and the same components are designated by the same reference numerals. The detailed description here is omitted.

In the refrigeration cycle of the present invention, as in the conventional case, the compressor 1, the condenser 3, the decompression device 4, the cooler 5 and the accumulator 6 are sequentially connected by the refrigerant pipe to form the main refrigerant circuit of the refrigeration cycle. . This main refrigerant circuit compressor 1
The gas cooler 2 is provided between the gas cooler inlet pipe 2a connected to the inlet side of the compressor and the gas cooler outlet pipe 2b connected to the outlet side of the compressor 1 to form a gas cooler circuit.

In the refrigerating apparatus having such a structure, as the first embodiment, the refrigerating apparatus is provided with the ambient temperature detector 9a for detecting the ambient air temperature as a detecting means for detecting that a part of the refrigerant discharged from the gas cooler 2 is liquefied. Is installed at an appropriate location near the, and the suction refrigerant of the compressor 1 is heated by the high pressure refrigerant to prevent liquefaction in the gas cooler 2,
As a bypass circuit means for bypassing the main refrigerant circuit, a bypass pipe 11a for connecting the gas cooler inlet pipe 2a and the compressor suction pipe 1d is provided, and the bypass pipe 11a is provided.
An electromagnetic opening / closing valve 7 and a throttling device 12 as opening / closing means for the flow path are provided in the middle of the process.

Then, the control device 8 as a control means using a microcomputer or the like is arranged at an appropriate place such as a showcase in which the refrigerating apparatus is installed, and as shown in the control circuit diagram of FIG. The temperature detection signal from the temperature detector 9a was introduced into the control device 8, and the control signal from the control device 8 was introduced into the electromagnetic on-off valve 7 provided in the bypass circuit means.

Next, the operation will be described. During normal operation, the electromagnetic opening / closing valve 7 of the bypass pipe 11a is closed, and the refrigerant flowing from the compressor 1 into the gas cooler inlet pipe 2a does not flow into the bypass pipe 11a and remains as it is. Inflow to 2. When the ambient temperature of the compressor 1 is low and the ambient temperature detected by the ambient air temperature detector 9a becomes equal to or lower than a constant value (AT1) as shown in FIG. 13, the controller 8 receives this temperature signal. Then, the capacity of the gas cooler 2 is increased and it is judged that a part of the refrigerant entering the compressor 1 may be liquefied or liquefied, and it is output to the electromagnetic opening / closing valve 7 to open it.

As a result, a part of the high-temperature high-pressure refrigerant discharged from the compressor 1 to the gas cooler inlet pipe 2a is partially discharged.
1a, the throttle pipe 12 and the suction pipe 1 of the compressor 1
Enter d. Therefore, the high-temperature and high-pressure refrigerant is mixed in the refrigerant sucked into the compressor 1 to be heated to a high temperature, and a higher temperature refrigerant is sent from the compressor 1 to the gas cooler 2. Even if the capacity increases, the refrigerant does not liquefy here.

Example 2. In the second embodiment, as shown in FIG. 3, as the bypass circuit means, the outlet pipe 3a of the condenser 3 is branched to form a bypass pipe 11b.
A heat exchanging part 13 for exchanging heat with the suction pipe 1d of the compressor 1 is provided in the middle of 1b, the tip of the bypass pipe 11b is reconnected to the outlet pipe 3a of the condenser 3, and a branch point is provided upstream of the connection point. An electromagnetic opening / closing valve 7 as an opening / closing means for the bypass passage is provided in the outlet pipe 3a of the condenser 3 which is the main refrigerant circuit located on the further downstream side.

In normal operation, the bypass pipe 11b
The solenoid on-off valve 7 is open, and the condenser 3 is connected to the outlet pipe 3a.
The entering refrigerant does not flow into the bypass pipe 11b, but directly flows into the pressure reducing device 4 through the refrigerant pipe of the main refrigerant circuit. When the controller 8 determines that the gas cooler 2 may liquefy the refrigerant, the controller 8 outputs the refrigerant to the electromagnetic opening / closing valve 7 and closes it. Thereby, the outlet pipe 3a of the condenser 3
Of the refrigerant flows into the bypass pipe 11b and reaches the heat exchange section 13, where it exchanges heat with the refrigerant in the suction pipe 1d to the compressor 1 to heat the refrigerant in the suction pipe 1d.

As a result, as indicated by the broken line in the Mollier curve diagram of FIG. 12, the superheat of the suction refrigerant increases, the discharge refrigerant temperature rises, and the higher temperature refrigerant is sent from the compressor 1 to the gas cooler 2. Therefore, the temperature of the gas cooler outlet pipe can be maintained in the superheat range, and even if the capacity of the gas cooler 2 increases, the refrigerant does not liquefy here.

When the electromagnetic on-off valve 7 is opened, the flow resistance of the bypass pipe 11b is larger than that of the refrigerant pipe of the main refrigerant circuit, so that the refrigerant does not flow toward the bypass pipe 11b. If the valve 7 is provided at the branch portion with the bypass pipe 11b and is a three-way valve, the flow path can be switched more reliably.

Example 3. In the third embodiment, as shown in FIG. 4, the gas cooler inlet pipe 2 is used as a detecting means for detecting that a part of the refrigerant discharged from the gas cooler 2 is liquefied.
a and the gas cooler outlet pipe 2b, the discharge pipe 1c from the compressor 1, the shell 1e of the compressor 1, etc., at any part of the high temperature part of the refrigeration cycle, in the illustrated example, the gas cooler outlet pipe 2b. A temperature detector 9b for detecting the temperature of the location is provided.

Then, as shown in the characteristic curve diagram of FIG. 13, when the ambient temperature becomes a constant value (AT1), the refrigerant is condensed,
When liquefaction starts and the temperature of the gas cooler outlet pipe 2b coincides with the condensing temperature, the temperature TI1 of the gas cooler inlet pipe 2a and the temperature TS of the shell 1e of the compressor 1 at this time
1. The temperature TO1 of the discharge pipe 1c of the compressor 1 and the temperature TC1 of the gas cooler outlet pipe 2b are experimentally obtained in advance, and these values are set in the control device 8, for example, the temperature attached to the gas cooler outlet pipe 2b. When the temperature detected by the detector 9b becomes lower than the set value TI1, the control device 8 outputs it to the electromagnetic on-off valve 7 provided in the bypass pipe 11a or the bypass pipe 11b to open or close the compressor to open the compressor. 1. Heat the refrigerant sucked into 1.

Example 4. FIG. 5 shows a fourth embodiment. In addition to the structure of the above-mentioned embodiment, a temperature detector 9b is attached to the two-phase portion of the condenser 3 to detect a means for detecting that a part of the refrigerant is liquefied. Install multiple. Ambient temperature is constant (AT1)
The condensing temperature in the condenser 3, which decreases correspondingly, becomes equal to the temperature TC1 of the gas cooler outlet pipe 2b, but this condensing temperature TC1 and the temperature of another refrigeration cycle high temperature part, for example, the gas cooler. The temperature of the outlet pipe 2b is compared with the temperature TC1, and when the difference becomes a certain value or less, in this case, if it is 0, the control device 8 outputs it to the electromagnetic on-off valve 7 to operate it and compress it. The refrigerant sucked into the machine 1 is heated. Therefore, the control device 8 can determine from these two temperatures that the refrigerant discharged from the gas cooler 2 is in a state of being easily liquefied, so that the detection accuracy is improved.

Example 5. FIG. 6 shows a fifth embodiment, in addition to a temperature detector 9b for detecting the temperature of one of the high temperature parts of the refrigeration cycle, as a detection means for detecting that part of the refrigerant discharged from the gas cooler 2 has been liquefied. A pressure detector 10 for detecting the condensation pressure in the condenser 3 is provided on the outlet side of the condenser 3.

Since the temperature and the pressure uniquely correspond to each other in the process of condensation, the condensation pressure when the ambient temperature has a constant value AT1 is obtained in advance, and this value is set in the control device 8. The condensation pressure detected by the pressure detector 10 is compared with the temperatures of other high temperature parts of the refrigeration cycle, and when the difference becomes equal to or less than a certain value, it is judged that the condensation and liquefaction of the refrigerant have started, and the control is performed. The device 8 outputs the electromagnetic on-off valve 7 and operates it to heat the refrigerant sucked into the compressor 1. In this case as well, the control device 8 can determine from the two data of the temperature and the pressure that the refrigerant discharged from the gas cooler 2 is easily liquefied, so that the detection accuracy is improved.

Although the output from the control device 8 to the electromagnetic on-off valve 7 is on / off controlled in the above embodiment, the present invention is not limited to this, and the phase control or voltage control as shown in FIGS. Each temperature detector 9a, 9b and pressure detector 1
It is also possible to output to the electromagnetic on-off valve 7 according to the detected value of 0. In such a case, the flow rate can be adjusted by adjusting the opening / closing degree of the electromagnetic on-off valve 7, and thereby the degree of heating can be adjusted.

[0044]

As described above, the refrigerating apparatus of the present invention is
According to the first aspect of the present invention, even if the refrigerant from the gas cooler is liquefied due to a low ambient temperature, the refrigerant discharged from the gas cooler is heated by the bypass circuit to increase the temperature of the discharged refrigerant. As a result, higher temperature refrigerant is sent from the compressor to the gas cooler, the gas cooler outlet pipe temperature can be maintained in the superheat range, and even if the capacity of the gas cooler increases, the refrigerant will not liquefy here. Therefore, it is possible to prevent the compressor from being damaged due to the liquefied refrigerant being sucked into the compressor.

According to the second aspect of the present invention, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, the internal temperature of the bypass circuit is detected based on the ambient temperature detected by the ambient temperature detector. The refrigerant can heat the compressor suction refrigerant, the discharge refrigerant temperature rises and higher temperature refrigerant is sent from the compressor to the gas cooler, and the gas cooler outlet pipe temperature can be kept in the superheat range. Even if the capacity of the cooler increases, the refrigerant does not liquefy here, and damage to the compressor due to the suction of the liquefied refrigerant into the compressor can be prevented.

According to the present invention as set forth in claim 3, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, between the gas cooler inlet pipe and the gas cooler outlet pipe,
Based on the temperature of the high temperature part of the refrigeration cycle detected by the temperature detector that detects the temperature of one of the high temperature parts of the refrigeration cycle, such as the discharge pipe from the compressor or the compressor shell, the refrigerant in the bypass circuit is the refrigerant sucked into the compressor. The temperature of the discharged refrigerant rises, and the higher temperature refrigerant is sent from the compressor to the gas cooler, and the temperature of the gas cooler outlet pipe can be kept in the superheat range, increasing the capacity of the gas cooler. However, the refrigerant is not liquefied here, and damage to the compressor due to suction of the liquefied refrigerant into the compressor can be prevented.

According to the present invention as set forth in claim 4, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, between the gas cooler inlet pipe and the gas cooler outlet pipe,
The compressor suction refrigerant is heated by the refrigerant in the bypass circuit based on a plurality of data of the temperature of one of the high temperature parts of the refrigeration cycle, such as the discharge pipe from the compressor and the compressor shell, and the temperature of the two-phase part of the condenser. Therefore, the temperature of the discharged refrigerant rises, and the higher temperature refrigerant is sent from the compressor to the gas cooler, and the temperature of the gas cooler outlet pipe can be kept in the superheat range, even if the capacity of the gas cooler increases. Here, the refrigerant does not liquefy, and damage to the compressor due to the suction of the liquefied refrigerant into the compressor can be prevented.

According to the fifth aspect of the present invention, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, between the gas cooler inlet pipe and the gas cooler outlet pipe,
Discharge pipe from the compressor, compressor shell, etc., based on a plurality of data of a temperature detector that detects the temperature of any of the high temperature parts of the refrigeration cycle and a pressure detector that detects the condensation pressure,
The refrigerant in the bypass circuit can heat the compressor suction refrigerant, the discharge refrigerant temperature rises, and the hotter refrigerant is sent from the compressor to the gas cooler, and the gas cooler outlet pipe temperature is also kept in the superheat range. Even if the capacity of the gas cooler increases, the refrigerant does not liquefy here,
It is possible to prevent damage to the compressor due to suction of the liquefied refrigerant into the compressor.

According to the present invention as set forth in claim 6, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, the bypass pipe connecting the gas cooler inlet pipe and the compressor suction pipe is heated to a high temperature. Since the refrigerant that is made to have a high pressure can heat the refrigerant sucked into the compressor, the temperature of the discharged refrigerant rises and the higher temperature refrigerant is sent from the compressor to the gas cooler,
The gas cooler outlet pipe temperature can also be maintained in the superheat range, and even if the capacity of the gas cooler increases, the refrigerant does not liquefy here, and damage to the compressor due to suction of the liquefied refrigerant into the compressor occurs. It can be prevented.

According to the present invention as set forth in claim 7, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature, the condenser outlet pipe is branched, and heat is exchanged with the compressor suction pipe on the way. The refrigerant that is sucked into the compressor can be heated by the bypass pipe provided with the heat exchange section, so the temperature of the discharged refrigerant rises and the higher temperature refrigerant is sent from the compressor to the gas cooler. Even if the capacity of the gas cooler increases, the refrigerant does not liquefy here, and damage to the compressor due to suction of the liquefied refrigerant into the compressor can be prevented.

According to the present invention as set forth in claim 8, even if the refrigerant from the gas cooler is liquefied due to a decrease in ambient temperature or the like, a plurality of detecting means for detecting the liquefied refrigerant are provided. When the difference between the detection values input from is less than a certain value, the control means outputs an operation signal to the solenoid on-off valve,
Since the refrigerant can be heated and fine control can be performed, it is possible to prevent damage to the compressor due to suction of the liquefied refrigerant into the compressor.

According to the ninth aspect of the present invention, even if the refrigerant from the gas cooler is liquefied due to a low ambient temperature, the opening / closing degree of the electromagnetic on-off valve is adjusted according to the detection value input from the detection means. The temperature of the refrigerant discharged to the gas cooler can be raised by heating the refrigerant sucked into the compressor by controlling it so as to change the temperature of the refrigerant. Can prevent damage.

[Brief description of drawings]

FIG. 1 is a refrigerant piping diagram showing a first embodiment of a refrigeration system of the present invention.

FIG. 2 is a control circuit diagram for energizing the opening / closing means of the bypass circuit means of the refrigerating apparatus of the present invention.

FIG. 3 is a refrigerant piping diagram showing a second embodiment of the refrigeration apparatus of the present invention.

FIG. 4 is a refrigerant piping diagram showing a third embodiment of the refrigeration apparatus of the present invention.

FIG. 5 is a refrigerant piping diagram showing a fourth embodiment of the refrigerating apparatus of the present invention.

FIG. 6 is a refrigerant piping diagram showing a fifth embodiment of the refrigeration apparatus of the present invention.

FIG. 7 is a curve diagram of energization control for the opening / closing means of the refrigerating apparatus of the present invention.

FIG. 8 is a curve diagram showing another example of energization control for the opening / closing means of the refrigerating apparatus of the present invention.

FIG. 9 is a refrigerant piping diagram of a conventional refrigeration system.

FIG. 10 is an explanatory diagram of a compressor of the refrigeration system.

FIG. 11 is a Mollier curve diagram showing a refrigerant temperature.

FIG. 12 is a Mollier curve diagram of another example showing the refrigerant temperature.

FIG. 13 is a characteristic curve diagram showing a relationship between ambient temperature and detected temperature.

[Explanation of symbols]

 1 ... Compressor 1a ... Motor 1b ... Cylinder 1c ... Discharge pipe 1d ... Suction pipe 1e ... Shell 2 ... Gas cooler 2a ... Gas cooler inlet pipe 2b ... Gas cooler outlet pipe 3 ... Condenser 3a ... Condenser outlet pipe 4 ... Reduced pressure Device 5 ... Cooler 6 ... Accumulator 7 ... Electromagnetic on-off valve 8 ... Control device 9a, 9b ... Temperature detector 10 ... Pressure detector 11a, 11b ... Bypass pipe 12 ... Throttle device 13 ... Heat exchange section

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yukinobu Nagano 1-1-1, Yamate, Funabashi-shi, Chiba Inside Nippon Funetsu Co., Ltd. (72) Inventor Masaru Konishi 1-1-1, Yamate, Funabashi-shi, Chiba No. 1 in the Funabashi Works of Nippon Steel Co., Ltd. (72) Hidetoshi Kimura 1-1-1, Yamate, Funabashi City, Chiba Prefecture No. 1 in Funabashi Works of the Nippon Steel Co., Ltd. (72) Zenjiro Ishii 1-1, Yamate, Funabashi City, Chiba Prefecture No. 1 Nippon Steel Co., Ltd. in Funabashi Works (72) Inventor Haruo Sakano 1-1-1, Yamate Funabashi City, Chiba Prefecture In Japan Funabashi Co., Ltd. (72) Inventor Oishi Zendo Yamate Funabashi City, Chiba Prefecture 1-1-1 Nihon-Ken Co., Ltd. Funabashi Works

Claims (9)

[Claims] 1. A gas connected between a main refrigerant circuit composed of a compressor, a condenser, a pressure reducing device, and a cooler, and a pipe communicating with the cylinder of the compressor and a pipe communicating with the inside of the compressor shell. In a refrigerating apparatus having a gas cooler circuit composed of a cooler, a detection means for detecting that a part of the refrigerant discharged from the gas cooler is liquefied, and a gas cooler that heats a refrigerant sucked in by a high-pressure refrigerant. A refrigeration apparatus for preventing the liquefaction of the main refrigerant circuit, and a control means for controlling the opening and closing of the flow path of the bypass circuit means by the output from the detection means. . 2. The refrigerating apparatus according to claim 1, wherein the detecting means is a temperature detector for detecting the ambient air temperature. 3. The temperature detector for detecting the temperature of any one of the high temperature portion of the refrigeration cycle, such as the discharge pipe from the compressor, the compressor shell, etc., between the gas cooler inlet pipe and the gas cooler outlet pipe. The refrigeration system according to claim 1. 4. The temperature of a high temperature part of the refrigeration cycle, such as between the gas cooler inlet pipe and the gas cooler outlet pipe, the discharge pipe from the compressor, the compressor shell, etc., and the temperature of the two-phase portion of the condenser. The refrigerating apparatus according to claim 1, wherein the refrigerating apparatus is a plurality of temperature detectors respectively detecting and. 5. A temperature detector for detecting a temperature of a high temperature portion of a refrigeration cycle, such as a discharge pipe from a compressor, a compressor shell, or the like, wherein the detection means is between a gas cooler inlet pipe and a gas cooler outlet pipe. The refrigerating apparatus according to claim 1, which is a pressure detector that detects a condensation pressure. 6. The refrigerating machine according to claim 1, wherein the bypass circuit means is a bypass pipe that connects the gas cooler inlet pipe and the compressor suction pipe, and a flow path opening / closing means and a throttle device are provided in the middle of the bypass pipe. apparatus. 7. A bypass pipe in which a bypass circuit means branches the condenser outlet pipe and is provided with a heat exchange section for exchanging heat with the compressor suction pipe, and the tip of the bypass pipe is reconnected to the condenser outlet pipe. 2. The refrigerating apparatus according to claim 1, wherein a passage opening / closing means is provided in a condenser outlet pipe which is a main refrigerant circuit located on the upstream side of the connection point and on the downstream side of the branch point. 8. The control means, when a plurality of detection means are provided, outputs an operation signal to the flow path opening / closing means of the bypass circuit means when the difference between the detection values input from the plurality of detection means becomes equal to or less than a certain value. The refrigerating apparatus according to claim 1, which outputs. 9. The refrigerating apparatus according to claim 1, wherein the control means controls so as to change the degree of opening / closing of the flow path opening / closing means of the bypass circuit means according to the detection value input from the detection means.